1 to 10 of 482
Sort by

Blog Entry
SQL Sparse Indexing for Db2 z/OS

Sparse indexing has been around for a number of versions. The history of these on the z/Os side goes back to originally helping with non-correlated subqueries in V4, then star joins in V7, to hashing support of these indexes in V10. Since V10, I have seen more and more use of sparse...

Tony Andrews's profile image

Blog Entry
SQL Query Writing Tips

Calisto Zuzarte gave a great presentation on writing SQL for performance at the IDUG 2018 North America conference. Check it out at

Blog Entry
SQL Tuning for Db2 - Where to Start by Eddy Coppens

SQL Tuning for Db2 - Where to Start by Eddy Coppens Even on the school benches I noticed that my teachers where not well taught themselves when it came to SQL. They just copied the text from their books onto the school board not giving us much insight on the matter. Once working for a...

Eddy Coppens's profile image

Blog Entry
Some of my favorite tunings tips and tricks for DB2 by Joe Geller

Joe Geller discusses some favorite tuning tips for Db2 in this video recorded at IDUG EMEA in Lisbon last month. Enjoy!

David Simpson's profile image

Blog Entry
DB2 LUW Version Preview Features by George Baklarz

DB2 LUW Version Preview Features It's inevitable that you see a couple of DB2 Fix Packs every year and place the readme document in a drawer somewhere for perusal later when you are not busy. While the Fix Packs may contain fixes (well that is what they are primarily meant for,...

Blog Entry
IDUG Tech Talk: Vital Statistics - What You Should Know About DB2 for LUW Catalog Statistics

The DB2 for Linux, UNIX and Windows query optimizer is responsible for choosing optimal query access plans, however it can't do its job properly without vital information about your data and database objects. The RUNSTATS utility has been used for years by database administrators to collect...

Blog Entry
DB2 LUW ‘Performance First Aid’ with monreport.dbsummary

Investigating performance problems doesn’t have to be hard. There are some basic steps you can take to find common bottlenecks in your system – ‘performance first aid’ if you will. We’re going to look at some of these basic problems and how to find them, using just DB2’s built-in capabilities....

Steve Rees's profile image

Blog Entry
IDUG Tech Talk: The ABCs of Filter Factors (aka Selectivity)

Tuning of SQL queries requires understanding why DB2 chose a particular access path and determining whether or not that access path should perform as expected. The key to this is understanding what filter factors are, how they are used by the Optimizer and how to get DB2 to better estimate them ...

Joe Geller's profile image

Blog Entry
The Rise and Fall of Dynamic SQL (Performance!)

The Rise and Fall of Dynamic SQL (Performance!) by: George Baklarz In this article we are going to examine some tuning options that a DBA has available to help improve dynamic SQL performance. The Life and Times of a Database Administrator (DBA) The life of a database administrator is...

Blog Entry
SQL Enhancements in DB2 12 ESP for z/OS

SQL Enhancements in DB2 12 ESP for z/OS Disclaimer: Information regarding potential future products is intended to outline IBM’s general product direction and it should not be relied on in making a purchasing decision. The information mentioned regarding potential future products is not a...